A contactor, as a widely used control component, is mainly used in a control circuit to switch on/off a circuit remotely and control start/stop of an electric motor, and may constitute a motor starter with an appropriate thermal relay or an electric protection device to protect a circuit in which overloading may occur. The contactor may be used in light industrial, metallurgical, chemical, coal mine, mechanical, hoisting, railway, shipbuilding and communication industries.
CN Utility Patent Application CN2091028U (Patent Document 1) discloses a vacuum magneto control point contactor comprising a vacuum seal cavity and a coil outside the vacuum seal cavity.
CN Utility Patent Application CN2342458Y (Patent Document 2) discloses a three-phase AC three-pole single-break point direct-driving contactor having three movable contacts and three fixed contacts corresponding to the three movable contacts in position.
CN Invention Patent Application CN101017740A (Patent Document 3) discloses a relay comprising a body, a movable contact and a fixed contact on the body, and an iron grating sheet for arc-extinguishing between the movable contact and the fixed contact nearby a moving direction line of the movable contact.